Ignition apparatus



Nov. 10, 1936. C;- H DAvls, 1R 2,060,556

` IGNITION APPARATUS Original Filed Feb. 1l', 1952 INVENTOR es /ddzs Jl.

ATTORNEYS Patented Nov. 10, 1936i PATENT OFFICE IGNITION APPARATUS Charles H. Davis, Jr., deceased,

Ind., by Anderson,

John T. Fitzsimmons,

late of Anderson, administrator,

Ind., assigner to General Motors Corporation, Detroit, Mich., a corporation of Delaware Original application February 11, 1932, Serial No.

592,289, now Patent No. 2,016,669, dated October 8, 1935.

Divided and this application July 25, 1934, Serial No. 736,845

8 Claims.

This invention relates to ignition timing distributor units for internal combustion engines and particularly for engines having a relatively large number of cylinders or spark gaps and requiring the use of a relatively massive ignition timer cam and distributor rotor and is a division of the copending application S. N. 592,289 filed February l1, 1932, now matured into Patent No. 2,016,669, of October 8, 1935.

Some trouble has been experienced with ignition timer distributor units for multi-cylinder engines because upon sudden acceleration of the engine a relatively heavy strain is placed upon the driving connections between the main drive shaft of the timer distributor unit and the cam and distributor rotor. This difficulty is encountered particularly because of the unusual mass of the cam and rotor to be accelerated whenever the engine is suddenly accelerated. It is an object of the present invention to over come these diiiiculties by certain improvements in the construction of the driving connections leading to the cam and distributor rotor.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawing:

Fig. 1 is a longitudinal sectional View o-f an ignition timer distributor unit embodying the present invention.

Fig. 2 is a sectional view on the line 2-2 of Fig. 1.

Fig. 3 is a perspective View of a portion of the driving connection leading to the timer cam and distributor rotor.

Figs. 4, 5, and 6 are plan views of modified forms of the driving member shown in Fig. 3.

Referring to Fig. 1, the numbers 20 and 2| designate ignition timer housing members secured together by screws such as shown at 22 thereby enclosing a chamber 23 which receives a centrifuga] device for controlling the timing of the ignition. The member 20 provides a tubular shank 24 received by a well in an engine frame which supports the timer. The shank 24 provides a bearing 25 for a shaft 26 carrying a gear 2'1 which meshes with a gear driven by the engine. The shaft 26 carries adjacent its upper end a collar 28 which is supported upon a thrust washer 29 bearing against an upper end of a tubular boss 30 which is in effect an extension of the shank 24. The shaft 26 is attached at its upper end to a Weight plate 3| which bears against the collar 28 and which is attached by riveting over the annular end portion 32 of the shaft 26, said end portion surrounding an internal bore 33 of the shaft 26. The -plate 3| carries studs 35 which pivotally support laminated weights 36 spot welded together and slidable across ribs 38 formed in the plate 3|. The weights 36 have lever arms 36 cooperating with lever arms 40 of a bar 4 I.

Pins 50 secure together the bar 4|, a spacer plate 45 and a Weight retainer plate 46 coextensive with the plate 45 and having wings 41 which are offset from the portion 46 and which extend over the weights 36 to retain them loosely upon the ribs 38. The parts 4|, 45, and 46 have central holes which are aligned when vthese parts are assembled by the pins 50. The wall of the central hole through this assembly of parts is serrated and then the assembly is hardened and is pressed on an unhardened portion 42 of a cam carrying shaft 43 whose lower end portion 44 has a bearing in the internal bore 33 of the shaft 26.

One of the pins 50 is longer than the other and extends into a hole 5| in the weight plate 3|, the hole 5| being of a size such as to provide a means for stopping movement of the pin 50 within a prescribed range of movement. The weights 36 are urged toward the shaft by spring 52 connecting the posts 35 with the posts 50.

The posts 59 are not only connected the shaft 43 through parts 4|, 45, and 45 having a drive t therewith, but are directly connected with the shaft 43 by parallel cross-pins 53 driven through holes in the shaft 43. Each end of each pin 53 fits snugly into a groove 54 in each pin 50. In this manner the part 4| which is the driving member for the shaft 43 is securely anchored to the shaft 43 in such a manner that angular displacement cannot occur without disrupting the driving t between the parts 4|, 45, and 46 and the shaft part 42 and without also bending the pins 53. This construction is of course useful for ignition apparatus required to rotate in either direction.

The modified form of the part shown in Fig. 3 is shown in Fig. 4 in which one pin 53a is employed. This pin extends diametrically across the shaft 43 and has its ends bent so as to be received by the grooves 54 in each of the pins 56. Fig. 5 is similar to Fig. 4 with the exception that two pins 53h are employed, these pins 53h have tapered inner ends driven into tapered holes in the shaft 43.

The form shown in Fig. 6 is adapted for use in a distributor which is required to rotate in one direction only. One cross pin 53C is employed and the ends thereof are received snugly by the groove 54 of pins 50.

The shaft 43 is journaled in a ball bearing 6D received in a cup-shaped part 6| provided in the base of the housing 2|. The inner race of the bearing 6|) is retained upon a shoulder 62 of shaft 43 by a resilient C-washer 63 which is snapped into a groove 64 provided in the shaft 43. A spacer 65 is located between the washer 63 and the inner race of the bearing Ell.

The washer 63 provides a seat for a cam 1B having a center bore which fits over the upper end of the shaft 43. The upper end of the shaft 43 is .tubular in formation and is slit in order to provide four resilient wedging members 1| which are adapted to be wedged apart by an expanding member 12 against the inner wall of the bore of the cam 10 in order to tightly secure the cam 10 on the shaft 43 in the desired position of adjustment. The expanding or wedge member 12 is formed to provide a frustro-conical wedging portion 13 and has a central bore 16 to receive a wedge screw 11 whose threaded lower end screws into a hole tapped centrally in the shaft 43. The wedge 12 is permanently secured to the screw 11 by deforming the lower end of its conical portion 13, as indicated at 18 in Fig. l, into groove 19 provided by the screw 11. The cam 13 is provided with diametrically opposite notches for receiving' a lug 14 of the Wedge 12 as Shown in Fig. 1. 'I'hese notches 8|] are formed in a tubular extension 8| of the cam 10 which extension is received by suitably formed apertures in a distributor rotor block 9e in order that the cani 1K3 maf,7 drive the block 90.

The tightening of the screw 11 causes the wedge 12 to move longitudinally into the shaft 43 thereby urging the prongs 1| tightly against the cam 10. Since the wedge 12 is provided with lugs 14 directly drivingly connected with the cam '|11 it is apparent that the cam is bound rst to the shaft 43 due to friction which exists between the outer surfaces of the prongs 1| and the inner wall of the cam 1B and to friction which exists between the outer conical surfaces 13 of the wedge 12 and the inner conical surfaces of the prongs 1|. In this way a double binding effect is obtained by utilizing both the external and internal surfaces of the prongs 1|.

The cam 10 cooperates with a circuit interrupter mounted on a plate 86 supported by the housing member 2| and supporting an ignition condenser 81.

The rotor 9D carries a conducting rotor 9| which carries current from a center button 92 to alternate distributor posts 93. The rotor block carries a conducting rotor 94 for conducting current to alternate distributor posts 93. The conductor 94 is electrically connected with a brush bearing against a conducting ring 9G. The button 92 and ring Sii are connected, respectively, with posts 91 and 98 having threaded sockets for receiving threaded connector plugs, not shown.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming Within the scope of the claims which follow.

What is claimed is as follows:

1. In an ignition timer-distributor apparatus having a timer cam for operating a circuit interrupter and for driving a distributor rotor, the

combination comprising a shaft for driving the cam, a bar for driving the shaft, means for fixing the bar to the shaft, a stud connected with the bar, and a rod bearing against the stud and attached to the shaft.

2. In an ignition timer-distributor apparatus having a timer cam for operating a circuit interrupter and for driving a distributor rotor, the combination comprising a shaft for driving the cam, a shaft-driving bar having a driving press fit with the shaft, a stud connected with the bar at a substantial distance from the shaft and extending parallel thereto, and a rod projecting transversely from the shaft and engaging the stud.

3. In an ignition timer-distributor apparatus having a timer cam for operating a circuit interrupter and for driving a distributor rotor, the combination comprising a shaft for driving the cam, a bar secured to and driven by the shaft, studs carried by the bar, and a cross pin carried by the shaft whose ends engage said studs.

4. In an ignition timer-distributor apparatus having a timer cam for operating a circuit interrupter and for driving a distributor rotor, the combination comprising a shaft for driving the cam, a bar driving the shaft and having a press fit with the same, grooved studs carried by the bar, and cross pins carried by the shaft for engagement with the grooves of said studs.

5. In an ignition timer-distributor apparatus having a timer cam operating a circuit interrupter and for driving a distributor rotor, the combination comprising a shaft for driving the cam, a shaft driving bar having a driving press fit with the shaft, means carried by the bar and located at a substantial distance from the shaft, said means extending beyond the plane of the bar, and means projecting from the shaft and engaging the means carried by the bar.

6. In an ignition timeredistributor apparatus having a timer cam for operating a circuit interrupter and for driving a distributor rotor, the combination comprising, a shaft for driving the cam, a weight hold-down plate fixed to the shaft, a bar fixed to the shaft and carrying studs near its extremities, and cross pins carried by the shaft and engaging the studs.

7. In an ignition timer-distributor apparatus having a timer cam for operating a circuit interrupter and for driving a distributor rotor, the combination comprising, a shaft for driving the cam, a shaft-driving assembly fixed to the shaft, said assembly comprising, a spacing member, a weight hold-down member, a bar, and a stud carried by the bar and passing through the holddown member and the spacing member to hold said members in a fixed relation with respect to the bar and to each other, and means extending from the shaft and engaging the studs.

8. In an ignition timer-distributor apparatus having a timer cam for operating a circuit interrupter and for driving a distributor rotor, the combination comprising, a shaft for driving the cam, a shaft-driving assembly fixed to the shaft, said assembly including a retaining plate, a bar. and studs fixed to the bar and extending through the plate to hold the retaining plate in a fixed relation with respect to the bar, and means extending through the shaft and bearing against the studs.

JOHN 'I'. FITZSIMMONS, Administrator of the Estate of Charles H. Davis,

Jr., Deceased.

Ii l) 

